<template>
  <view>
    <view class="search-box">
      <uni-search-bar @input="input" :radius="100" cancelButton="none"></uni-search-bar>
      
      <!-- 搜索建议列表 -->
      <view class="sugg-list" v-if="searchList.length !== 0">
        <view class="sugg-item" v-for="(item,i) in searchList" :key="i" @click="gotoDetail(item)">
          <view class="goods_name">{{item.goods_name}}</view>
          <uni-icons type="right" size="16"></uni-icons>
        </view>
      </view>
      
      <!-- 搜索历史 -->
      <view class="history-box" v-else>
        <!-- 标题区域 -->
        <view class="history-title">
          <text>搜索历史</text>
          <uni-icons type="trash" size="17" @click="clean"></uni-icons>
        </view>
        <!-- 列表区域 -->
        <view class="history-list">
          <uni-tag :text="item" v-for="(item,i) in histories" :key="i" @click="gotoGoodsList(item)"></uni-tag>
        </view>
      </view>
    </view>
  </view>
</template>

<script>
  export default {
    data() {
      return {
        timer:null,
        // 搜索关键词
        kw:'',
        // 搜索建议的结果列表
        searchList:[],
        // 搜索历史
        historyList:[]
      };
    },
    onLoad(){
      this.historyList = JSON.parse(uni.getStorageSync('kw') || '[]')
    },
    methods:{
      // 搜索框的input输入事件
      input(e){
        // 清除timer对应的延时器
        clearTimeout(this.timer)
        // 重新启动一个延时器，没有触发输入事件，就为关键词赋值
        this.timer = setTimeout(() => {
          this.kw = e
          // 根据关键词，查询搜索建议列表
          this.getSearchList()
        }, 500)
      },
      
      // 获取搜索建议结果
      async getSearchList(){
        // 判断搜索关键词是否为空
        if(this.kw.length === 0){
          this.searchList = []
          return
        }
        // 发起请求，获取搜索建议列表
        const {data: res} = await uni.$http.get('/api/public/v1/goods/qsearch',{query: this.kw})
        if(res.meta.status !== 200) return uni.$showMsg()
        this.searchList = res.message
        
        this.saveSearchHistory()
      },
      // 跳转到商品详情页面
      gotoDetail(item){
        uni.navigateTo({
          url: '/subpkg/goods_detail/goods_detail?goods_id=' + item.goods_id
        })
      },
      // 保存搜索历史
      saveSearchHistory(){
        // this.historyList.push(this.kw)
        const set = new Set(this.historyList)
        set.delete(this.kw)
        set.add(this.kw)
        // console.log(set)
        this.historyList = Array.from(set)
        
        // 将历史记录持久化存储到本地存储
        uni.setStorageSync('kw',JSON.stringify(this.historyList))
      },
      // 清除历史记录和本地缓存
      clean(){
        this.historyList = []
        uni.setStorageSync('kw','[]')
      },
      //跳转到商品列表
      gotoGoodsList(kw){
        uni.navigateTo({
          url: '/subpkg/goods_list/goods_list?query=' + kw
        })
      }
      
    },
    computed:{
      histories(){
        return [...this.historyList].reverse()
      }
    }
  }
</script>

<style lang="scss">
  
.search-box{
  position: sticky;
  top: 0;
  z-index: 999;
}

.sugg-list{
  padding: 0 5px;
  .sugg-item{
    display: flex;
    font-size: 12px;
    align-items: center;
    justify-content: space-between;
    padding: 13px 0;
    border-bottom: 1px solid #DCDFE6;
    .goods_name{
      // 单行文本，不许换行
      white-space: nowrap;
      // 溢出部分隐藏
      overflow: hidden;
      text-overflow: ellipsis;
    }
  }
}

.history-box{
  padding: 0 5px;
  .history-title{
    display: flex;
    height: 40px;
    justify-content: space-between;
    align-items: center;
    font-size: 13px;
    border-bottom: 1px solid #DCDFE6;
  }
  .history-list{
    display: flex;
    flex-wrap: wrap;
    margin-top: 5px;
    .uni-tag{
      margin-right: 5px;
    }
  }
}
</style>
